Former petroleum minister Shahid Khaqan Abbasi is expected to be elected Pakistans new prime minister.

Islamabad: A close ally of ousted Pakistani Prime Minister Nawaz Sharif on Monday submitted papers in parliament to become new premier, part of a two-part plan by the ruling party for a smooth transition that will see Mr Sharif's brother take the reins later.

Former petroleum minister Shahid Khaqan Abbasi is expected to be elected new prime minister on Tuesday by Mr Sharif's Pakistan Muslim League-Nawaz party's majority of lawmakers.

Pakistan's Supreme Court ordered Mr Sharif disqualified from office last week over unreported income uncovered during a sweeping investigation of his finances.

The court also ordered a separate criminal investigation into Mr Sharif and his family in its ruling, which the ousted prime minister's allies have portrayed as political meddling but opposition leader Imran Khan has hailed as a victory for the rule of law.

Mr Abassi on Monday stressed he would continue Nawaz Sharif's policies. His tenure is expected to last only about two months until Mr Sharif's brother, Shahbaz, becomes eligible to be prime minister by winning a parliamentary by-election.

"The policies we had until Friday, we will continue with that," he added.

Mr Sharif's PML-N party won elections in 2013 and holds a majority with 188 seats in the 342-member parliament, so it should be able to swiftly install its choice of premier, barring any defections from its own ranks.

Nawaz Sharif said over the weekend he was shocked by Friday's Supreme Court ruling disqualifying him from office over unreported income from a company owned by his son in Dubai. Mr Sharif said the monthly salary - equivalent to $2,722 - was nominal and he never actually received any of it.

The Supreme Court employed little-used Article 62 of the Constitution, which calls for the dismissal of any lawmaker deemed dishonest, to remove Sharif. His allies believe the verdict smacks of judicial overreach. Others say privately that elements of the military had a hand in the process.